1. Field of the Invention
The present invention relates in general to improved truck sideframes for railway cars. More specifically, but without restriction to the particular use which is shown and described, this invention relates to a lighter weight truck sideframe.
2. Description of the Related Art
As conventional, railcar trucks are the wheeled vehicles that ride on the tracks and support the railcar body. Each truck includes wheel sets which include two wheels spaced transversely from each other and joined by a transversely extending axle. Transversely spaced truck sideframes are supported on the wheel sets. The truck sideframes are longitudinally elongated and define longitudinally spaced, downwardly opening pedestal jaws which are mounted on the journal bearings of the wheel sets. Transversely extending between each truck sideframe is a bolster on which is mounted the car body.
The Association of American Railroads (xe2x80x9cA.A.R.xe2x80x9d) sets forth structural requirements for the various components of the trucks, including the truck sideframes. The requirements for the truck sideframe include specific strength and fatigue resistant capabilities for extended service of the truck sideframe. Because the railcar truck sideframes must exhibit high strength, truck sideframes are conventionally made of cast steel, which contributes a significant part of the total weight of the railway car. In the rail line shipping industry, weight limits are placed on shippers of goods for preserving the safety and conditions of the track. Consequently, the quantity of goods that may be carried by a railcar is affected by the total weight of the railcar body, the trucks and accompanying railcar components, such as the truck sideframe. Accordingly, a reduction in the weight of the railcars, including the truck sideframes, will result in an increase in the total capacity of goods shipped by a rail line owner. Therefore, it is highly desirable to reduce the weight of the truck sideframe while maintaining the strength and fatigue resistance capabilities of the sideframe, as required by the A.A.R.
Accordingly, an object of the present invention is to reduce the overall weight of a railway car by reducing the weight of the truck sideframe. It is another object of the invention to reduce the weight of the truck sideframe without a decrease in strength or durability. Yet another object of the invention is to minimize core seams and core shifting by reducing the number of cores used. Still another object of the present invention is to minimize chaplets in the drag by setting the core in the mold on its prints.
Briefly stated, the present invention involves lightening the truck sideframe by removing the double wall of the truck sideframe tension member. Removing this significant mass of metal requires reinforcement of the truck sideframe in the following areas: 1) extending the rib under the spring seat out to the column wear plate wall; 2) increasing the thickness under the radius at the spring seat in the side wall; 3) increasing the width of the truck sideframe at its centerline; 4) increasing the depth of the truck sideframe at its centerline; 5) locally sloping the top compression member toward the side walls and locally increasing the interior radius between the sloped top compression member and each side wall to prevent the top compression member from buckling; and 6) splitting the side window with a reinforcing rib, the reinforcing rib defining a raised portion to prevent the sidewall from buckling. Significantly, with these truck sideframe modifications, the resulting truck sideframe construction is of lighter weight than conventional truck sideframes and exceeds the A.A.R. requirements for strength and durability.
The full range of objects, aspects and advantages of the invention are only appreciated by a full reading of this specification and a full understanding of the invention. Therefore, to complete this specification, a detailed description of the invention follows, after a brief description of the drawings.